Yah Ive had the same issue except with Charlie always eating Nana's poop. I asked my vet why he was doing it and he said that the younger pup will eat the older pups poop because they feel they need the extra nutrients. It could be the same case with your puppy except for eating her own. I tryed the pineapple but he still ate it..
I wonder if theres somthing else to give them?